The Structure Elucidation And Preliminary Evaluation In The Western Paleogene Of Tahe Oil Field

The seismic data structural interpretation and the reservoir prediction technology had a long history in oil and gas exploration field. Structural interpretation technology was improved with the development of seismic data level and the progress of interpretation means. It exists three stages early or late. The first stage is V1—Optical paper to interpret the section. The second stage is the horizontal stack of paper section interpretation of two-dimensional simulation tape recording and digital recording. The last one is migration section stack of two-and three-dimensional Interpretation stage. The reservoir prediction technology has also own development of years and it become one front porch for the development of seismic data structural interpretation. Presently seismic reservoir prediction technology has been matured, and a set of reservoir prediction technology has been formed, such as seismic inversion, seismic attribute analysis, AVO analysis, which play an important role in lithology, morphology, physical properties and prediction of oil and gas. The reservoir prediction technology was regarded the leading technology and it has been improved constantly in practical application.This article is based on the research of the three-dimensional seismic data for the western Paleogene of Tahe oil field. Under the guide of Exploration Seismology and Structural Geology or sequence stratigraphy. After we had finished and absorbed the research findings of predecessors, we started in fine horizon calibration and the buliding of the Stratigraphic framework and then used a series of fine structure interpretation techniques such as:automatic tracking of seismic section, multiple line joint, horizontal slice, coherence cube, seismic attribute analysis and the inversion of seismic data inversion. After all, we finished the fine structural interpretation of the three-dimensional seismic data in the target area. We implemented the fault, the fault block and provided the reliable basic data for the the study of structural features and exploration target evaluation in this area. The main contents are as follows:1. We find out the precise tectonic features of the three target horizons such as the top interface of Suweiyi formation(T23), the bottom interface of Suweiyi formation(T24) and the bottom interface of Kumugeliemuqun formation(T30) through the combination of three-dimensional seismic data and well data.2. According to the research of waveform classification technique under the Seismic facies analysis. The sand body of Suweiyi formation and Kumugeliemuqun formation in the target horizons all has a trend from the northeast to southwest toward the spread characteristic in the plane of the display. This proved that the source was came from the northeast.3. From inversion results of the reservoir seismic data, we knew the upper sandstone of Kumugeliemuqun formation had a main development for the underwater distributary channel deposit of the fan delta front and estuary dam deposition,which the major source of the sand body was from the North East. And the provenance source for the lower sandstone section of Suweiyi formation was mainly from the northeast. It is further showed that the provenance source were form northeast under the ample supply and the main prograded fan delta deposition of Suweiyi formation.4. Combined with the sandstone thickness map of Kumugeliemuqun formation and Suweiyi formation for the characteristic analysis of sand body distribution, we found that the Paleogene clastic reservoirs of the target area is mainly controlled by the local microstructure control and it is formed mainly by two types of oil and gas reservoirs. One is consist of the fault and the nose structure, the other one is the oil and gas reservoir of the traction structure anticlinal.5. Through the analysis of the existing thought with the exploration and development results. We considered that the study area was based on the fault nose reservoir and micro-structure anticlinal reservoirs. As a result of the development of sandstone pinch-out for the transgressive system tracts with Kumugeliemu formation. There should be existed oil and gas reservoirs of lithologic and lithologic structural composite reservoir.